During the 1970s and 1980s, vehicle manufacturers began to use electronic systems to control engine functions and diagnose engine problems in an attempt to meet federal emissions standards set up by the Environmental Protection Agency (EPA). In the mid-1980's, the California Air Resources Board (CARB) approved a set of regulations requiring vehicles to be equipped with On-Board Diagnostic (OBD) systems to control and regulate emission and engine-control related components. The OBD system included circuitry and other electromechanical components that recorded engine and emission-related malfunctions using diagnostic trouble codes (DTCs). Stored in memory, the DTCs could later be retrieved by technicians to quickly determine the direct cause of the malfunctions and make necessary repairs.
OBD systems installed on vehicles included, among other things, an engine control module that monitored the engine controls and emission related components, a malfunction indicator lamp (MIL) located on an instrument panel and other supporting circuitry and memory. When a malfunction was detected by the OBD system, the MIL illuminated to provide notice to the vehicle operator of an engine or emissions malfunction. At the same time, the OBD system stored in memory the DTCs corresponding to the specific malfunction detected.
In addition to standard tailpipe testing equipment which measured exhaust output and content, state emission testing facilities were subsequently equipped with OBD-equipment that connected to the OBD system of a vehicle and retrieved stored DTCs by way of a data link connector (DLC). As a consequence, inspection and maintenance programs could quickly and efficiently determine whether a vehicle's specific engine control and emission system was functioning normally. For instance, to detect whether the engine control system of the OBD was functioning normally, an inspector could perform a standard key on engine off (KOEO) test by examining the responsiveness of the MIL under KOEO conditions. By retrieving the DTCs stored by OBD systems, an inspector could similarly review a history of generated trouble codes and diagnose the vehicle's road-worthiness.
In the late 1980's and early 1990's California developed and approved a new set of regulations, a second generation OBD system (OBD-II) for use in newly manufactured vehicles. OBD-II built upon the first generation OBD system and incorporated various technical advancements including, among other things, the ability to monitor engine misfires and catalysts efficiencies. Although the first and second generation of OBD regulations were originally only required in California, Federal emission regulations quickly followed. Operating under the framework of the Clean Air Act of 1990, the EPA adopted California's OBD-II regulations in the mid-1990s and required certain vehicles manufactured in 1996 and later to be equipped with OBD-II systems. In addition to requiring OBD-II systems, the Clean Air Act requires states to perform vehicle checks of OBD-II systems by way of mandatory programs which read generated DTCs and indicate whether the vehicle is safe and robust in terms of today's emission control standards. As of 1998, the EPA adopted new Federal OBD-II standards based on California's OBD-II regulations for certain newly manufactured vehicles.
Prior to adoption of the Federal standards, states typically utilized standard tailpipe testing equipment to evaluate and determine whether the exhaust volume and content met prescribed limits. Unlike traditional tailpipe testings, mandatory inspection and maintenance programs using OBD-II systems look for broken or malfunctioning emissions control components and detect potential or existing malfunctions before it leads to higher vehicle emissions. As a result, OBD-II technology benefits motorists, repair technicians and the environment. Motorists benefit because it monitors vehicle's performance each time the vehicle is driven and immediately identifies problems, allowing service to be performed before serious problems develop. Repair technicians benefit because it enables them to accurately and quickly diagnose problems by downloading DTCs vis-a-vis a data link connector (DLC). Lastly, because the OBD-II system identifies problems that cause increased vehicle emissions, the environment benefits from a lack of pollutants.
As emission and engine maintenance technology has improved from the 1970s to the present, Federal and state governments have adopted new technologies to measure vehicle emissions and keep our vehicles cleaner and safer. As a result of first and second generation OBD systems, tailpipe analyzer tests and legacy equipment are no longer required for vehicles manufactured in 1996 and later. While emissions testing has become standard across the United States, state-run facilities generally include complicated testing protocols and methodologies and expensive and mandated ancillary equipment to read and interpret DTCs. While individual vehicle owners may utilize state-run facilities to receive feedback based upon their vehicle's emissions and engine performance, the inspection and maintenance programs are generally not required for each vehicle until a vehicle reaches a prescribed age. Because state facilities are generally not available to the casual user or are inconveniently located, private manufacturers have marketed custom software and hardwired OBD testing equipment. While vehicle owners no longer need to visit state-run facilities to perform engine and emissions tests, the equipment sold by private manufacturers is neither economical, streamlined or user-friendly. Therefore, a need exists for OBD testing equipment which features state-of-the-art equipment allowing user-friendly testing processes to encourage self-service testing practices among vehicle owners and/or trained vehicle inspectors.
It is further noted that current OBD testing equipment has few, if any, security systems in place to prevent fraudulent reporting of engine and emissions data and thus is susceptible to abuse. Accordingly, a further need exits for OBD testing equipment having security and/or tamper-resistant features designed to alleviate this problem.